Miniature/micro-scale power generation system

ABSTRACT

A miniature/micro scale Tesla-type turbine (MG) with a stalk (ST), a top (T), a bottom (B), five central disks (D) having a aproximate thickness of seven microms. The turbine (MG) also includes inter disk spacing of approximately seven microms and a disk spacing of 25 microms between the upper and the lower of the five disks (D) and the top disk (DT) and the bottom disk (DB). The top (T) and bottom (B) each have conducting elements (C) opposing the magnetic elements (MN and MS) located along the rotating turbine disks (DT and DB).

FIELD OF INVENTION

The instant invention lies in the field of miniature/micro-scale powergeneration systems; more particularly, the invention lies in the fieldof Tesla turbine design for use in miniature/micro-scale powergeneration.

BACKGROUND

The state of the art of miniature/micro-scale power generation systemsis rudimentary. Miniature generation systems today largely consist ofsmall refrigerator sized systems that generate power during emergencies,but not at high efficiencies.

Typical miniature systems can be broken down into two categories: fuelcell systems and micro-generation. Fuel cells can be efficient if thereis a secondary heat usage; otherwise, it is difficult to manufacturefuel cells that are highly efficient (>50%). Further, fuel cells requirea catalyst which is usually a rare earth metal such as platinum orpalladium. These materials can be extremely expensive and keep theoverall costs of the fuel cell high.

Micro-scale power generation systems have been built in labs. No highlyefficient, cost effective manufacturing technique or production line isknown to exist at this time for these systems. The systems consist ofscaled down traditional combustion turbine designs and/or miniaturereciprocating engines. Some of the systems are premised upon theutilization of semiconductor fabrication techniques in order to build tosmall dimensions. None of these systems have proven themselvescommercially viable.

Micro-fabrication techniques utilized to construct MEMS (micro electromechanical systems) in general have limited themselves to produce MEMSof simple structures, having limited movement of mechanical parts. Thelimited movement usually does not include freely moving parts. Complexthree-dimensional systems with moving parts have not been readilyproposed to be manufactured utilizing chemical polish, wafer bonding,etching and the like techniques.

However, as illustrated herein, versions of micro-fabrication techniquessuch as utilized to construct MEMS, may be effectively used tomanufacture miniature/micro/sub-micro scaled turbine/generators of theinstant design. Use of such manufacturing techniques to solve problemsassociated with building complex three-dimensional units ofmicro-machinery with moving parts, including techniques wherein theunits significantly “self-assemble” themselves, combines fortuitouslywith versions of a historically obscure and disfavored turbine designThe combination offers surprising compatibility for self-assembly.

The instant invention, contrary to tradition, teaches employment on aminiature/micro/sub-micro scale of an anomalous turbine design for powergeneration. The Tesla-type turbine, which historically has been referredto as a “curiosity”, is taught to be suited for miniature/micro-scale.Features of, even disadvantages of, Tesla turbines on a macro scale aresuitable for, and even possibly advantageous for, aminiature/micro/sub-micro scale.

The system of the instant invention is disclosed as an efficientscaleable system, scalable both in dimension and combination. Variablesized power sources could be assembled utilizing the basicturbine/generators. An array/matrix format could be structured to employunitary inlet and exhaust channels, as well as built-in heat recoveryand secondary cycle capabilities, so that overall efficiencies of thesystem could be raised.

In summary, the invention discloses a miniature or micro-scaledTesla-type turbine design, and associated generator, adapted forefficient small scale operation as well as high volume productiontechniques, including a design that lends itself to real-time controland dispatching systems, and which might include an array/matrix ofturbines, permitting the utilization of efficiency improvementtechniques. It is foreseeable for essentially an entire system to befabricated from generally the same material (silicon-carbide).

SUMMARY OF THE INVENTION

The invention comprises a miniature/micro scale Tesla-type gas turbineand associated generator that generates less than 1 horsepower, at leastsingly, when not matrixed or arrayed together. The impelling fluid couldbe liquid, but is typically gas. (Inter disk spacing is typically largerfor liquids.)

The term “miniature/micro” is used herein to indicate a size rangingfrom centimeters to sub micron. This is opposed to a range of a meter orlarger, which would be referred to as macro scale. The turbine includesat least one chamber having a fluid inlet and a fluid outlet and asource of pressurized fluid, preferably combustion gas, in fluidcommunication with the inlet. A set of disks, preferably 3 or more inparallel, are journaled for rotation in the chamber, the diskspreferably having a diameter of less than 10 centimeters. In someembodiments, the diameter could be 1 centimeter or less. An inter diskspacing is preferably defined between the disks of less than 1/10^(th)of a diameter and in some embodiments of less than 1/20^(th) of adiameter, or even smaller. The interdisk spacing may be 0.1 mm or less.Experience indicates that such spacing, of 0.1 mm or less, promoteslaminar flow.

The chamber and disks are structured in combination such that fluid froman inlet radially traverses an inter disk path, preferably enteringtangentially to a disk set's peripheral edge and exhausting centrally toa disk set. Preferably the fluid exhausts nonturbulently through asubstantially unobstructed central area. The absence of a shaft, and anoncentral disk attachment arrangement, furthers such nonturbulentexhaust.

The turbine/generator may include a generator with a set of conductingregions and a set of opposing magnetic regions, each set located upon anelement that moves with respect to the other, preferably each setlocated upon one of a chamber wall or an opposing rotating disk, forsimplicity of structure and efficiency.

Disks of a set that function as vanes in a Tesla-type turbine areusually flat and attached together in parallel. However, the disks couldbe curved or bent, all or in a portion, and could have protrusions. Diskedges may be further modified to direct gas flow. Alternatively, diskedges may be designed to collect energy of a gas striking a disk edge.Inter disk movement of fluid, characteristic of a Tesla-type turbinedesign, is preferably radially out to in, following a spiral pattern,although more complex movements could be possible. Disks may containprotrusions. Disks in a set may be attached by elements that alsofunction as vanes.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing description of preferred embodiments of the invention ispresented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formor embodiment disclosed. The description was selected to best explainthe principles of the invention and their practical application toenable others skilled in the art to best utilize the invention invarious embodiments. Various modifications as are best suited to theparticular use are contemplated.

FIG. 1 illustrate a turbine on a miniature scale. The scale is ininches. FIG. 1 illustrates a side view, FIG. 1A illustrates a cutawayside view, FIG. 1B illustrates a top view and FIG. 1C illustrates a sideview of the turbine, and disks.

FIGS. 2A and 2B illustrate a micro scale turbine. FIGS. 2A and 2Billustrate side views of the turbine portion. The figures are not toscale visually, and are not to scale between the horizontal and verticaldirections. The difference in scale facilitates visual representation.

FIGS. 2C and 2D illustrate a turbine disk with side and/or edgeprotrusions.

FIGS. 3, including FIG. 3 A, FIG. 3B and FIG. 3C, represent a preferredembodiment of a generator design.

FIGS. 4-7 illustrate features of casing designed for a microturbine/generator. FIGS. 4-7 are not necessarily to scale visually or inthe horizontal vs. vertical directions, for ease of visualrepresentation. FIG. 4 illustrates casing design. FIG. 5 illustratesfuel and air intake as well as exhaust. FIG. 6 offers a top view of amicro turbine disk. FIG. 7 offers a view of a micro turbine/generatorfootprint.

FIGS. 8 and 9 illustrate the matrixing of turbine/generators in anarray. FIG. 8 illustrates an energy matrix with input and exhaustchannels. FIG. 9 illustrates a micro turbine/generator matrixed with anair input plane and an air exhaust plane matrixed into the array.

FIG. 10 illustrates a top view of a wafer indicating a manufacturingarray for micro turbine/generators.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Design of Miniature Tesla Turbine/Generators:

Tesla-type gas turbine designs as disclosed herein may be regarded asversions of, and/or improvements to, an original Tesla turbine designedby Nicoli Tesla in the early 1900's. That Tesla turbine design has notenjoyed significant commercial exploitation. If treated at all in textbooks, the Tesla turbine is referred to as a “curiosity.” Thedisadvantages of a Tesla design vis-à-vis other turbine designs includesthe fact that Tesla turbine efficiency increases with a reduction in theinter disk spacing between the disks. Tesla designs for turbines havebeen somewhat of an anomaly historically and largely ignored in gasturbine studies.

One aspect of the instant invention teaches that such a prior anomalousor curious design on a macro scale can have advantages in the field ofminiature/micro scaled turbines. One Tesla design disadvantage on amacro scale, namely the increase in efficiency of the design with thedecrease in inter disk spacing, could become an advantage on a miniatureor micro scale. Further, manufacturing techniques on a micro scale, inparticular stereo lithography and chemical deposition, can maintainexcellent control of horizontal dimensions (<1 um) over near.macroscopic (>1 cm) dimensions. Maintaining tolerances when scaleschange by factors exceeding 10,000 is extremely difficult withtraditional means scaled manufacturing techniques.

A miniature/micro scale Tesla-type turbine of the instant designinvolves a disk type turbine, nominally employing flat disks, whichdesign can enable the creation of extremely flat turbine/generators,having miniature/micro fabrication and array/matrxing advantages.

FIGS. 1 and 1A-1C illustrate a prototype miniature scaled Tesla turbine.The scale units of the prototype are in inches. Turbine housing 1includes horn mount 10 with chamber 20 for the receipt of pressurizedfluid, preferably air. Air enters through chamber 20, thence through gasport element 17 and into a 90 degree horn 14. The pressurized air inhorn 14 exits port 21 peripherally to disks 2. The pressurized airenters tangentially to the set of disks 2, which together with disk base3 and disk top 7 are journaled for rotation within turbine housing 1.Arrow 18 in FIG. 1B illustrates the spiral movement of the pressurizedair, which could be any pressurized fluid, in the turbine housing andwithin the inter disk spacing. FIGS. 1A and 1C illustrate the inter diskspacing defined by disks 2 as well as between disk base 3 and disk top7. Pressurized fluid spirals from a periphery of the disks 2 to anexhaust cavity at the center of the disks, illustrated by arrow 18 inFIG. 1B. Pressurized fluid exits the turbine in a direction of arrow 19,shown in FIGS. 1A and 1C.

FIG. 1C illustrates inter disk spacing for a miniature turbine. Thedisks of the miniature turbine are a 0.05 inches thick. Spacers 5 withconnecting rods 6 maintain the disks in spaced relationship. The radiusof the disks, r₁, as indicated in FIG. 1C is approximately one inch, andthe radius of the exhaust is approximately one fifth of that amount.

FIG. 1A illustrates a lower bearing shaft 4 and upper bearing shaft 8.Lower bearing shaft 4 extends within lower bearing 9. Upper bearingretainer 12 retains upper bearing 11. Bottom horn spacer 13 lies betweenhorn 14 and horn support 16. Horn support 16 and horn spacers 15 and 13help adjust the location of the horn to provide input fluid or gas.

FIGS. 2A and 2B illustrate a micron sized turbine and generator. (Notethat FIGS. 2A and 2B utilize different and/or varying vertical andhorizontal dimensional scales, for representational ease.) Targeteddimensions are indicated on FIG. 2A; if the target proves difficult toachieve in practice or in mass production, the illustrated scale may notbe a preferred production scale.

FIGS. 2C and 2D illustrate a turbine disk D having surface protrusionsPR and/or edge protrusions DE.

An aspect of one preferred micro design, indicated by the scale of FIG.2A, is the entire disk set being kept as flat as possible. This meansthat a favorable ratio of material structure thickness to the strengthof the material (such as exemplified by silicon carbide) should be takeninto account in the design. In one preferred design, illustrated in FIG.2A, the overall dimension of a generator and turbine could beapproximately 250 microns thick with the other dimensions being 1-cm by1-cm.

Preferred embodiments of a Tesla turbine for the instant invention aredesigned for maximum single cycle efficiency. One preferred designutilizes 5 individual turbine disks D, although 3 disks may suffice. Inthe micro turbine design of FIG. 2A each disk is shown 7 microns thickand spaced 7 microns from the next disk. This extremely thin and smallinter disk spacing may be possible, and cost effective, through usingsemiconductor fabrication techniques.

FIG. 2A illustrates a side view of a micro turbine generator with aturbine stalk ST. A portion of the micro generator illustrated includestop T and bottom B. Vertical scale is indicated to the right in thedrawing, (which again is not consistently to scale). Horizontal scale isindicated at the bottom. Visually, neither the vertical scale nor thehorizontal scale are fully consistent, for representational ease. Fivedisks D are indicated as attached and located within the micro turbinesMG. Each of the five central disks D has a thickness of approximatelyseven microns. The inter disk spacing is also approximately sevenmicrons. A spacing of 25 microns is indicated between the upper andlower disk of the set of five disks D and a top disk DT and a bottomdisk DB. Such larger inter disk spacing may be advisable in order tocontrol any heat generated in the turbine, so as not to affect thegenerators. Top disk DT and bottom disk DB are indicated as havingimplanted magnetic north and magnetic south portions. Pressurized fluid,as indicated by arrow 18, enters the inter disk spacing between the fivedisk set in accordance with arrow 18. Although not indicated on drawing2A, disks D may be attached to stalk ST by spokes SP at the centerregion as in FIG. 6. Such spokes would permit pressurized fluid,entering from the direction of arrow 18, to exhaust from the disks at acentral area, as indicated by arrow 19. Top portion T and bottom portionB each have conducting elements C opposing magnetic elements MN and MSlocated along rotating turbine disks. The turbine is journaled forrotation of stalk ST within cavity CA of bottom section B and topsection T.

Between each of the Tesla disks some air flow impediments, includingstructural elements and possibly extra protrusions, may be placed. Seefor instance elements 5 and 6 of FIGS. 1A and 1C of the prototype. Theseimpediments may serve two roles. First they can serve as what Teslareferred to as air buckets, which catch air or gas and require it to goaround the impediment. Secondly, they can attach together and helpcreate rigidity between individual disks so that each disk can bethinner. Overall small disk spacing and thinness of the disks can bevaluable in a design from an efficiency standpoint.

Tesla taught in his original patent that a Tesla-type turbine works offof two primary physical effects. The first is a surface cohesion of theair or gas moving between the disks. In todays language this is a zeroslip boundary layer. In this regard, the disks should be preferablyextremely tightly coupled, which improves the overall efficiency of theturbine. Secondly, Tesla taught that turbines work off of directionalair flow and the conversion of the velocity of the air flow into thephysical movement of the turbine. Therefore, gradual changes in thevelocity of the air or gas more effectively extract the energy withinthe system. To this extent, it is preferred for an overall ratio betweenthe inner and outer diameter of a turbine disk to be great. Preferablyair or gas flows from a disk peripheral area inwardly, radially, towardthe disk center, as illustrated by arrow 18 in FIG. 1B, and exhauststhrough a center region of the disk, as illustrated by arrow 19 in FIG.1A. Thus, air or gas preferably flows within the Tesla turbine in acentrifugal fashion. This centrifugal air flow helps ensure that thereis a gradual change in flow and allows the turbine a maximum time toextract energy out of the flow, since the air or gas on the outerportions of the disk is moving at a much higher velocity than the air orgas at the center of a disk. The relative linear velocity between theinlet and exhaust locations on the disk is generally given by r₁/r₂where r₁ is the radius of the disk and r₂ is the radius of the exhaustport. Therefore, the greater the differential between the inner andouter diameter of the turbine disk, the greater the potential velocitydifferential. This velocity differential has a direct correlation withthe efficiency of the turbine. Further, in order for a high velocitychange to not build up pressure in the turbine, the input and outputports should be sized accordingly. By combining a maximum inner/outerdiameter ratio with properly sized input/output ports, preferred basicdimensional ratios of a Tesla turbine can be derived.

Manufacturing Possibilities—High Volume Processes:

Tesla turbines are three dimensional structures preferably havingclosely spaced parallel disks or plates functioning as vanes. Nozzlesmay be incorporated into the design for directing fluid flow through thevanes, (that is through the inter disk spaces) from outside to inside,exhausting through a central region of the disks or an upper and/orlower region, generating the rotational forces acting on the turbine.The closer the plates are spaced the greater the efficiency of theturbine in transferring the energy of a rapid and/or expanding gas intorotational forces.

Such Tesla turbine design is suited for miniature and/ormicro-fabrication techniques, such as planar manufacturing processes,where a horizontal spacing of features can be tightly controlled toextremely small dimensions. Potential benefits of a combination of MEMS(Micro ElectroMechanical Systems) with Tesla turbine manufacture exist.

The use of filler material and support material, independently removableto create a freestanding object, has not been widely practiced in microfabrication. However the removal of filler material followed by an etchor dissolution of support material could allow a turbine of the instantdesign, which turns freely within a casing, to be essentially“self-assembled”.

Alternately, the use of a web process for the instant turbineconstruction is possible. Web processes have generally been consideredfor manufacturing essentially two dimensional objects, such asband-aids, newspapers or adhesive labels. (While these examples arestrictly speaking three dimensional, they can be regarded as twodimensional.) Although the use of a web manufacturing process has nothitherto been considered a suitable manufacturing process for creating athree dimensional object such as a turbine, the instant design may be anexception. Further, the concept of screen-printing a generator has notbeen fully appreciated. Screen-printing conductive materials is anemerging area. Screen-printing magnetic particles has not been practicedon practical scale. The combination of the two processes, web and screenprinting, is possible for the creation of a turbine and generatoraccording to preferred embodiments herein.

Illustrated Fabrication of Turbine/Generator—MEMS

One possible method of fabrication for an embodiment for the instantsystem, enhancing its practicability, teaches utilizing semiconductorfabrication techniques. Ideally, for these purposes, the shape of theturbine would be essentially flat and have a width to height ratio of atleast 10×. FIGS. 2A and 2B illustrate views of portions of possibleturbine and generator designs.

One possible micro fabrication technique for turbines and generatorscould utilize two wafers. Each wafer could have multiple partialturbines/generators G, as indicated in FIG. 10 (top view of an entirewafer W). The binding of the two wafers together could create theindividual power sources.

Actual feature dimensions of preferred micro turbines and generators aremuch larger than the feature dimensions of that utilized insemiconductor chips. Today's feature size capabilities of semiconductorfabrication equipment is about 0.18 micron. The smallest feature sizeenvisioned for the preferred turbines and generators of the instantinvention is likely approximately 1-2 microns. Therefore, the instantturbines and generators would require approximately an order ofmagnitude less in feature tolerances, a manufacturing benefit.

To continue the illustration in more detail, one fabrication process,illustrated in FIG. 2B, could begin with a substrate S. The substrate'sactual height is not necessarily relevant, but one of its sides shouldbe a polished surface which is extremely flat and smooth. Thefabrication process would preferably be broken down so that two uniqueplanes are created. Each plane could then subsequently be bondedtogether so that a full power source is created. FIG. 2B illustratesonly one plane.

A turbine and generator could be “self assembled” by removing,subsequent to bonding, “support structure” SS utilized to holdindividual planes together during processing and bonding. Such “supportstructure” could be removed by either chemical dissolving orchemical/heat dissolving, for instance.

One possible fabrication process could include utilizing four differenttypes of structures: turbine/casing structure TCS; electric generatorstructure GS; filler structure FS; and support structure SS. Acombination of the use of these structures could enable the fabricationof a micro turbine and generator. The selected and independent removalof the filler FS and the support structures SS could enable a turbineand generator to have free motion within a system that was built as asingle unit, without the assembly of each individual structureseparately.

A top plane of a turbine and generator and a bottom plane of the turbineand generator could have different processing steps, since each istrying to build different parts of the power source. For purposes ofillustration, a bottom plane could be a plane that includes a base, halfof a power transmission grid, and turbine/generator stalks and chamberwalls, as illustrated in FIG. 2B. The bottom plane could also includeportions of combustion chambers, air intakes, exhausts and nozzles,arranged for effective matrixing. A top plane, not specificallyillustrated herein, could contain the other portions of such elements,including continuing portions of the power transmission grid, exhaustgrid and fuel supply.

FIGS. 3A-3C illustrate an electric generator design for coupling to aturbine drive. FIG. 3A illustrates the placement of conducting elementsC and their interconnection, as is known in the art, for electric poweroutput. Elements C are illustrated affixed to bottom B or top T. FIG. 3Billustrates the arrangement of magnetic portions MN and MS, alternatelypolarized as magnetic north or magnetic south.

FIGS. 4-9 illustrate how individual turbines and generators of theinstant design could be matrixed, utilizing arrayed air intakes andexhausts. Starting with the individual unit, FIG. 4 illustrates a casingdesign for a micro turbine/generator. (Note that FIG. 4 is drawn withdiffering horizontal and vertical scales, which was done for ease ofrepresentation.) FIG. 4 illustrates the placement of exhaust port's EPand input nozzles IN suitable for a micro turbine and generator, as perFIGS. 2A and 2B. FIG. 4 also illustrates a combustion chamber CCcontaining glow line GL, which is a hot wire or high resistant wire forcombustion ignition.

FIG. 5 expands upon FIG. 4. FIG. 5 illustrates unitary exhaust shafts Ein communication with exhaust ports EP. FIG. 5 illustrates unitary airintake conduits A in communication with combustion chambers CC whichoutput into input nozzles IN. FIG. 5 illustrates the placement of fuellines FL. for feeding into combustion chambers CC.

FIG. 6 is a top view of a micro turbine MG in relation to the fluidinput nozzles, and FIG. 7 is a view of a micro turbine footprint.Indicated in the top view of the micro turbine in FIG. 6 is stalk STconnected by spokes SP to disk D. Arrow 18 indicates the movement of airor other pressurized fluid through the input nozzles to the centralexhaust.

FIG. 8 illustrates an energy matrix. Single cycle turbine generators arepresumed to be distributed within the matrix. FIG. 8 illustrates the useof unitary air conduits A and exhaust conduits E to supply an arrayedmatrix of generators. FIG. 9 illustrates an energy matrix having an airinput plane AIP and an air exhaust plane AEP attached at opposing ends.

The basic steps that could be utilized in the fabrication of a bottomplate and turbine are preferably chemical etch, chemical/physical vapordisposition, lithography, photoresist spin & development, annealing, andwafer cleaning/solvent cleaning. Deposited filler material and supportstructure could be selectively utilized to produce freely moving parts.The combination of such steps, as is known in the art, along withdepositing different materials and the utilization of different masks,could enable an entire fabrication of a turbine/generator plane.

Once a top plane and a bottom plane are fabricated, the next step wouldbe to remove the filler material utilized during the fabrication of theindividual planes. The filler material is utilized in the development ofthe planes to create the three dimensional structures that are requiredin the turbine and generator. This filler material is ideal whenutilizing a deposition technique where a gap needs to exist and thedeposition process would otherwise fill the gap. If a filler material isutilized, the gap is filled with this material which enables adeposition process to be utilized. The filler material is removed fromboth the top and bottom planes by utilizing a simple dissolventsolution. The wafers are bathed in this solution for a period of timesuch that all of the filler material is then removed.

An independently removable support structure assists “self assembly”.Self-assembling indicates that two individual planes are bonded togetherwhere the planes consist of rigid structures. The rigid structures aresubsequently processed to allow free movement.

Fabrication of three dimensional structures with moving parts, such as aturbine, typically requires a “pick and place” method to install themoving parts into the casing. It would be preferred to avoid or minimizepick and place steps. Thus, a preferred method would be to hold movingparts in place until the entire power source is assembled. A“self-assembly” method utilizing “support structure” eliminates pick andplace requirements. The support structure acts as a holding method forthe moving parts until the turbine and generator is assembled. Once anentire wafer is fabricated and assembled with another wafer, a processof removing the support structure makes the process a self-assemblyprocess. The support structure is made of a material resistant todissolving in the dissolvent utilized for the filler material. Thesupport structure, however, should remain dissolvable after repeatedannealing cycles.

In the fabrication steps of a top plane and a bottom plane, there couldbe requirements for metallic inserts into a silicon carbide structure orthe like in order to create a stator/rotor electric generator systemMetallic inserts on turbine disks themselves, as illustrated in FIG. 3B,are preferably magnetized. The magnetization of inserts could beaccomplished as a processing step during building of a plane. Once anentire plane is built, it might be more difficult to magnetizeindividual magnetic inserts. All of the magnetic inserts on an entirewafer would preferably be magnetized at once. This preferably entailsutilizing a template in which a current wafer is input and amagnetization step is then run for the wafer.

To summarize, possible steps of a fabrication process for a turbine andgenerator of the instant design are:

-   -   1. Polish substrate wafers for both a top and a bottom plane.    -   2. Process the top and bottom plane individually utilizing their        individual fabrication steps, including a magnetization step if        desired.    -   3. Prepare surfaces for wafer bonding.    -   4. Remove filler material from the top and bottom planes.    -   5. Align top and bottom planes and press together.    -   6. Wafer bond top and bottom planes to create a wafer of power        sources.    -   7. Remove support structure material from the power sources.        Illustrated Fabrication—Web Process

Alternately, in a web processing method, continuous strips of materialcould be used to form turbine rotating disks and fixed top bases andbottom bases, as well as spacers. The thickness of a strip wouldprobably be 0.5 mm or less. The width would at least be as great as aturbine diameter. The bonding of the individual strips would allowcreation of 3 dimensional structure.

Tractor holes in a strip could allow alignment for the processing stepsand the subsequent bonding steps.

A resist layer could be used to protect a metal strip during an etchingprocess to create raised features on a flat surface. Etching couldcreate, for instance, a bushing which would support the turbine disksand be a contact point to the housing. In addition shafts could beformed on the flat surfaces.

For a Tesla turbine, attachment elements joining individual plates couldbe simply shafts. The shafts can also collect energy from an acceleratedand/or pressurized fluid which causes the disks to rotate.

A magnetic material could be deposited in the form of a paste to createa generator. The paste could consist of fine magnetic particles in anappropriate carrier. Further steps could include: sintering magneticmaterial; inducing the material to the appropriate polarity withalternating North/South poles around each turbine; and punching a centerexhaust.

A plurality of the above web pieces could mate using the turbineshaft/vanes, and the turbine plates could be aligned to each other usingthe exhausts or the outer edges. Once the web pieces were appropriatelyaligned, they could be permanently welded, which would result in acompleted turbine.

Bases could be constructed in the same fashion as turbines. A continuousstrip of material would be selected. The thickness would be sufficientto support the forces generated by the turbine. Tractor feed holes couldbe punched, and a center exhaust also punched. Resist could be depositedto protect areas where etching is not desired. After etching one couldremove resist. This process would create the other half of the bushingon which a turbine would rotate. Appropriate generator coils could bescreen printed. Contacts also could be screen printed, Preferably onewould include a spacer construction, which is a composite of individuallayers which results in the necessary height to contain the turbine andgenerator structures.

A complete turbine casing (base, spacer, lid) could be similarly createdand assembled on this base.

The final assembly could entail a process similar to lamination. Onemajor difference would be that the turbine must be picked and placedinto the bushing on the base. Also when the lid is attached the bushingbetween the turbine and lid would have to be aligned.

The word “a” as used in the claims below refers to at least one.

A “set” means a plurality. Typically a set of disks are sized andstructured to be essentially identical, although that is not per senecessary.

An inter disk space is the space defined, in general, between two disks.Its key dimension is the distance, in general or for practical purposes,between two disks.

Usually disks are attached in parallel, but exceptions could be madewithout destroying the effectiveness of the system

The foregoing description of preferred embodiments of the invention ispresented for purposes of illustration and description, and is notintended to be exhaustive or to limit the invention to the precise formor embodiment disclosed. The description was selected to best explainthe principles of the invention and their practical application toenable others skilled in the art to best utilize the invention invarious embodiments. Various modifications as are best suited to theparticular use are contemplated. It is intended that the scope of theinvention is not to be limited by the specification, but to be definedby the claims set forth below.

1. A less than 1 horsepower Tesla-type turbine/generator, comprising: atleast two disks having a diameter of less than 10 cm, journaled forrotation in a chamber and defining a stator/rotor system of theturbine/generator; the disks defining at least one inter disk spacemeasuring less than one tenth of a diameter; the chamber having a fluidinlet and outlet structured in combination with the disks such thatfluid radially and inwardly traverses an inter disk path between inletand outlet; and a source of pressurized fluid in fluid communicationwith an inlet.
 2. The apparatus of claim 1 including an outlet locatedcentrally with respect to a disk.
 3. The apparatus of claim 1 whereinthe disks have a diameter of less than or equal to 1 cm.
 4. Theapparatus of claims 1 or 3 wherein the inter disk spacing is less than120^(th) of a disk diameter.
 5. The apparatus of claims 1 or 3 whereinthe disks define a centrally located, unobstructed fluid path fornonturbulent exhaust.
 6. The apparatus of claims I or 3 wherein an interdisk space is less than or equal to 0.1 mm.
 7. The apparatus of claim 1wherein a disk side contains a protrusion.
 8. The apparatus of claim 1including a chamber fluid inlet located peripherally with respect to adisk outer edge and a chamber fluid outlet located peripherally above orbelow a plurality of disks.
 9. The apparatus of claim 1 including atleast five disks.
 10. The apparatus of claim 1 wherein the disks areattached in parallel.
 11. The apparatus of claim 1 including at leastthree disks.
 12. The apparatus of claim 1 wherein the pressurized fluidincludes combustion gas.
 13. The apparatus of claims 1, 9 or 11 thatincludes at least a top or bottom disk defining a second inter diskspacing of at least three times a first inter disk spacing.
 14. Theapparatus of claim 1 wherein a set of magnetic regions are located on adisk and a set of conducting regions are located on a chamber wall. 15.The apparatus of claim 1 wherein a disk edge contains a protrusion. 16.The apparatus of claim 13 wherein a set of magnetic regions are locatedon a disk and a set of conducting regions are located on a chamber wall.17. The apparatus of claim 1 wherein the stator/rotor system comprises ashaftless generator, the generator including a set of conducting regionsand a set of opposing magnetic regions, each located upon one of a diskor a chamber wall.
 18. A method of generating less than 1 horsepower,comprising: spiraling pressurized fluid generally inwardly through atleast one inter disk space defined between a plurality of disksjournaled for rotation in a chamber; defining an inter disk space ofless than 0.5 mm; rotating the disks with the fluid; and generating thepower electrically by the movement of conducting regions throughmagnetic fields, the movement occasioned by the rotation.
 19. The methodof claim 18 including nonturbulently, substantially unobstructedlyexhausting fluid centrally from an inter disk space.
 20. The method ofclaim 18 including rotating Tesla-type turbine disks by spiraling fluidthrough an inter disk space of less than or equal to 0.1 mm.
 21. A lessthan 1 horsepower Tesla type turbine/generator, comprising: means forrotating a plurality of disks in a chamber by circulating pressurizedfluid radially inwardly through an inter disk space of less than orequal to 1 cm, the inter disk space defined by a plurality of disks ofdiameter of less than or equal to 10 cm; and means for generating thepower, associated with the chamber and rotating disks.
 22. The apparatusof claim 21 including means for nonturbulently exhausting fluidcentrally from an inter disk space.
 23. A less than 1 horsepower Teslatype turbine/generating method, comprising: a step for rotating aplurality of disks in a chamber by circulating pressurized fluidradially inwardly through an inter disk space of less than or equal to 1cm, the inter disk space defined by a plurality of disks of diameter ofless than or equal to 10 cm; and a step for generating less than 1horsepower associated with the chamber and rotating disks.
 24. Theturbine/generator of claim 21 wherein the disks are of a diameter ofless than or equal to 1 cm and the inter disk space is less than orequal to 0.5 mm.
 25. The generating method of claim 23 wherein the disksare of a diameter of less than or equal to 1 cm and the inter disk spaceis less than or equal to 0.5 mm.
 26. A matrixed array ofminiature/micro-scale less than 1 horsepower Tesla type turbinesstructured in combination as a generator.
 27. The method of claims 18 or23 including constructing the turbine/generator using MEMS.
 28. Theturbine of claim 1 constructed essentially of a silicon.
 29. The methodof claims 18 or 23 including constructing the turbine/generator usingweb processing.
 30. The apparatus of claims I or 21 wherein a disk sidecontains surface protrusions which catch fluid.
 31. The apparatus ofclaims I or 21 wherein a disk side contains a Tessla “air bucket”protrusion.
 32. The method of claims 18 or 23 that includes catching anddiverting fluid with a protrusion extending from a disk into an interdisk space.
 33. The method of claims 18 or 23 that includes catchinginter disk fluid with a Tessla air bucket.
 34. The apparatus of claims Ior 21 wherein the disks are not parallel.